Roberta Vinci of Italy rallied in the third-set to defeat Yanina Wickmayer 6-2, 3-6, 7-5 in the opening women's match of the Rogers Cup on Tuesday.
Vinci, ranked 28th, trailed 5-2 in the third set when she began winning points on her forehand against the Belgian.
She advanced to play 11th-seeded Ana Ivanovic, the 2006 Rogers Cup winner.
The match was played on the hardcourts at Uniprix Stadium, where the tournament began a day later than usual to accommodate the London Olympics.
In other matches, Chanelle Scheepers of South Africa rallied to beat Stephanie Dubois of Canada, 1-6, 6-3, 6-0; Ekaterina Makarova of Russia handled Urszula Radwanska of Poland 6-4, 6-2; and Tamira Paszek of Austria defeated Julia Goerges of Germany 6-2, 6-1 to earn a matchup with top-seeded Victoria Azarenka.
Azarenka is hanging onto the No. 1 world ranking by a thread and will have to hold off second-seeded Agnieszka Radwanska and No. 3 Maria Sharapova to stay on top. Sharapova can regain the top ranking if she wins the tournament, while Radwanska would need to win and have both Azarenka and Sharapova bow out before the quarterfinals.
"It's really exciting," said Azarenka, who captured her first grand slam title this year at the Australian Open. "We're all showing consistent tennis through the year."